The present invention relates to a traction control for automotive vehicles, and more particularly to a method of and a system for controlling a wheel slip at acceleration.
JP-A 2-233855 discloses a traction control wherein an engine performs a split cylinder operation on lean mixture to control the engine torque. According to this known control, the split cylinder operation is performed on lean mixture, i.e., a mixture with a predetermined air fuel ratio greater than the stoichiometry, even when the temperature of engine cylinders is elevated greatly due to engine operation on rich mixture during warm-up operation at very low ambient temperature or during operation at high speed with high or heavy load. Supply of oxygen rich lean mixture to each of the heated engine cylinders results in a rapid increase of combustion temperature, creating heat spot within the combustion chamber and thus inducing occurrence of knock. The combustion at increased temperature results in exhaust gas with excessively high temperature.
An object of the present invention is to improve a traction control of the above type such that a split cylinder operation is performed without occurrence of knock and without excessive increase in exhaust gas temperature.